Cylinder block and method of construction



April 3, 1956 R. c. HOFFMAN 2,740,393

CYLINDER BLOCK AND METHOD OF CONSTRUCTION Filed Oct. 27, 1952 3 Sheets-Sheet 1 Fascoe C Hoffman, BY

April 3, 1956 R. c. HOFFMAN CYLINDER BLOCK AND METHOD OF CONSTRUCTION Filed Oct. 27, 1952 3 Sheets-Sheet 2 m. R mm y 6 6 w w F fili agony TwWvr/a April 3, 1956 c, HOFFMAN 2,740,393

CYLINDER BLOCK AND METHOD OF CONSTRUCTION I Filed 00".- 27, 1952 3 Sheets-Sheet 3 IN V EN TOR. as'coe C Hoffman Wain/27K? CYLINDER BLOCK AND METHOD OF CONSTRUCTION Roscoe C. Hoffman, Detroit, lt-i'ich. Application October 27, 1%52, Serial No. 317,093 11 Claims; or. 123-495 This invention relates to cylinder blocks, and, more particularly, to cylinder blocks adapted for use in V- type internal-combustion engines.

Cylinder blocks of the type above referred to are conventionally made by pouring molten .metal into sand molds having suitable cores placed therein adapted to form openings or passageways in the castings. Such castings are inherently inaccurate since the molds and cores must be separated by vibration from their patterns and core boxes, respectively, and the surfaces of such castings, which have been poured in sand, are rough and pitted. Since the sand molds may be used only once,

skilled molders must be employed to make the molds and they are required to handle large amounts of sand with a resultant increase in the cost of manufacture of the blocks. Where accurate dimensions are required, such as in cylinder passageways and bearing supports, a relatively large amount of machining is necessary in order to remove excess material.

Relatively small openings, such as oil ducts, require further machining of the casting since such small openings cannot be produced in such molds; and since relatively thin wall sections cannot be cast in sand molds, the weight and cost of such castings is further increased.

Accordingly, an object of the present invention is to overcome the disadvantages present with cylinder blocks of the type above referred to and to provide a lightweight, relatively inexpensive cylinder block that may be accurately cast in permanent molds thereby permitting the use of relatively thin wall sections and obviating the necessity of machining or otherwise removing relatively large amounts of material therefrom.

Another object of the invention is to provide a cylinder block comprised of a plurality of transverse sections that may be easily and quickly integrated by brazing to form a complete V-type cylinder block.

Another object of the invention is to provide a cylinder block comprised of transverse sections that may be readily assembled and integrated to form a cylinder block having an desired even number of cylinders.

Another object of the invention is to provide a cylinder block comprised of transverse sections that may be cast in permanent molds without the use of cores.

Still another object of the invention is to provide a cylinder block that is simple in construction, economical of manufacture, durable, efiicient, and reliable in operation.

Yet another object of the invention is to provide an improved cylinder block suitable for use with aluminum and other light weight metals so as to obtain a reduced weight to horsepower ratio and better heat conduction. In the accomplishment of these objects, the present invention contemplates the use of relatively thin wall sections, reduced labor and relatively high production rates to compensate for the additional cost per pound of the aforementioned light weight materials.

With the above as well as other and in certain cases more detailed objects in view, which will become ap- 2,740,393 Patented Apr. 3, 1956 2 parent from the following detailed description and the appended claims, preferred but illustrative embodiments of the invention-are illustrated in the accompanying drawings, throughout the several views of which corresponding reference characters designate corresponding parts and wherein:

Figure 1 is a top plan view of .one form of the invention;

Fig. 2 is a perspective view of a center transverse section of the invention shown in Fig. 1;

Fig. '3 is a perspective view of the rear transverse ,section of the invention shown in Fig. l;

Fig. 4 is a perspective view of .the front transverse section of the invention shown in Fig. 1; and

Fig. 5 is a top plan view of another form of the invention.

Referring to the drawings, one embodiment of the invention is illustrated in Figures 1, 2, 3, .and 4, and is comprised of a plurality of transverse sections generally designated 10, 12, and 14. While a four-cylinder block is illustrated, it will be appreciated that any desired number of center sections such as 12 may be interposed between the rear section and the front section 14 :so that a cylinder block may be readily assembled having any desired even number of cylinders.

Cylindrical locating portions, adapted to accommodate asleeve cylinder (not shown), are formed by providing recesses such as 16, 18, 20, and 22 in :the .side walls of each section. It will be noted that the axes of the locating portions are offset longitudinally so that the block is particularly adapted to accommodate .QQII' necting rods connected side by side on the crank shaft.

The upper wall portion is provided with a plurality of raised boss portions such as 24 and 26 having openings such as 23 and 30 in which intake and exhaust valve cam followers may be inserted. Recesses such as 31 and 32 are also provided in the sideand upper walls, adapted to form oil drain-back holes when the sections are assembled. It will be appreciated that such openings formed .in the permanently molded casting eliminate a subs-tantial amount of machining.

The outer walls, such as 33, of each section perpendicular to the plane of the locating portions are ground or otherwise machined so as to form flat surfaces on which conventional cylinder heads may be fastened.

As illustrated in Figure 2, the end portions Maud of the cylinder locating portions are reduced in diameter so that the inserted cylinder sleeves abut :the reduced portions 34 and 35 while an annular space is provided which encompasses the cylinder sleeve so that .a coolant may be circulated to cool the block.

Center section 12 is provided with a downwardly extending center wall 36 having an opening .38 adapted to accommodate a earn shaft and a recess 40 adapted to serve as the upper support for a crank shaft bearing. Flange portions 42 and 44 are provided on the lower side of the center section 12 so that an oil pan may be fastened to the bottom of the block.

As illustrated in Figure 3, rear section 10 is provided with an end wall 46 having an opening 48 adapted to accommodate the cam shaft and a recess St) adapted to serve as the upper support for a crank shaft hearing. The lower side of the rear section is provided with flange portions 52 and 54 forming continuations of the pan fastening flanges 42 and 44.

The forward wall 56 of the front section 5141s provided with suitable raised pad portions 58 on which may be mounted cooling system fittings, an opening 60 adapted to accommodate the cam shaft and a recess 62 adapted to serve as the upper support for a crank shaft bearing. The lower side of the front section 10 is also provided with flange portions 64 and 66 for the oil pan.

The flat side surfaces of each section may be coined, ground, or machined before the sections are brazed to form the integrated cylinder block, and the cylinder sleeves or liners may be brazed to the sections at the same time that the sections are joined. v

It will be noted that the sections of the embodiment of the invention illustrated in Figure l are joined to adjacent sections in one vertical plane and that the axis of each cylinder is offset with respect to the transverse edge of each section. it will be appreciated that such sections can be moved through a grinder and/ or miller so that the joining and 80, sothat the axis of each cylinder locating portion coincides with the joining surfaces of the sections.

It will be appreciated that the cylinder locating portions are finish bored before the cylinder liners are inserted.

Such a stepped construction reduces the amount of metal that must be cast and subsequently removed since less draft is required to permit removal of a semicircular die section than a substantially U-shaped section. Such a construction is also advantageous when it is necessary to prevent the joining surfaces from passing through stud bosses and the like.

While two preferred embodiments of the invention have been shown and described, it will be understood that various changes and modifications may be made without departing from the scope and spirit of the invention. For example a cylinder block for an engine having horizontally opposed cylinders or in line cylinders could be formed in a similar manner.

What is claimed is:

l. A V-type cylinder block comprising a plurality of initially separate sections, said sections being joined together to form a block, each of said sections provided with a plurality of curved recesses adapted to form cylinder locating portions, the centers of curvature of the recesses in each of said sections being spaced with respect to each other along the longitudinal. axis of said block.

2. A V-type cylinder block comprising a front transverse section, a rear transverse section, and a plurality of center transverse sections interposed intermediate said front section and said rear section, said sections being joined together to form a block, each of said sections provided with a plurality of curved recesses adapted to form cylinder locating and cooling jacket portions, the centers of curvature of the recesses in each of said sections being spaced with respect to each other along the longitudinal axis of said block.

3. A V-type cylinder block comprising a front transverse section, a rear transverse section, and a plurality of center transverse sections interposed intermediate said front section and said rear section, said sections being 7 joined together along the transverse walls thereof to form a block, each of said sections provided with a plurality of curved recesses adapted to form cylinder locating portions. the centers of curvature of the recesses in each of said sections being spaced with respect to each other along the -longitudinal axis of said block, each of said sections also provided with an opening adapted to accommodate a cam shaft therein and a recess adapted to serve as a support for a crank shaft.

4. In a V-type cylinder block assembly, a plurality of transverse sections extending from side to side of the assembly and having transverse abutting walls, said sections being joined together along such abutting walls to form a block, each section including a crankcase portion and case portions being axially aligned longitudinally of the block assembly and said cylinder locating portions comprising curved, re-entrant, open-sided, oppositely directed and correspondingly positioned recesses located in said abutting transverse walls and coacting to define circular openings located partly in each of said sections, the centers of curvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said openings having their axes substantially radial with respect to, and longitudinally spaced along, the longitudinal axes ofthe crankcase portions.

5. In a- V-type cylinder block assembly, a plurality of transverse sections extending from side to side of the assembly and having transverse abutting walls, said sections being joined together along such abutting walls to form a block, each section including a crankcase portion and transversely spaced cylinder locating portions the axes of whichareoiisetwith' respect to said abutting walls, said crankcase-portions being axially aligned longitudinally of the block assembly and the cylinder locating portions comprising curved, re-entrant, open-sided, oppositely directed'and correspondingly positioned recesses located in said abuttingtransverse walls and coacting to define circular openings located partly in each of said sections, the centers of curvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said openings having their axes substantially radial with respect to, and longitudinally spaced along, the longitudinal axes of the crankcase portions.

6. In a V-type cylinder block assembly, a plurality of transverse sections extending from side to side of the assembly and having transverse abutting walls, said sections being joined together along such abutting walls to form a block, each section including a crankcase portion and transversely spaced cylinder locating portions the axes of which coincide with the abutting walls of each section adjacent said locating portions, said crankcase portions being axially aligned longitudinally of the block assembly and said cylinder locating portions comprising curved, re-entrant, open-sided, oppositely directed and correspondingly positioned recesses located in said abutting transverse walis and coacting to define circular openings located partly in each of said sections, the centers of curvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said openings having their axes substantially radial with respect to and longitudinally spaced along, the longitudinal axes of the crankcase portions.

7. In a V-type cylinder block assembly, a front transverse secticn, a rear transverse section, and a plurality of center transverse sections, said sections extending from side to side of the assembly and having transverse abutting walls, said sections being joined together along said abutting walls to form a block, each section including a crankcase portion and transversely spaced cylinder locating portions the axes of which are offset with respect to said abutting walls, said crankcase portions being axially aligned longitudinally of the block assembly and the cylinder locating portions comprising curved, re-entrant, opensided, oppositely directed and correspondingly positioned recesses located in said abutting transverse walls and coacting to define circular openings located partly in each of said sections, the centers ofcurvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said openings having their axes substantially radial with respect to, and longitudinally spaced along, the longitudinal axes of the crankcase portions.

8. in a V-type cylinder block assembly, a front transverse section, a rear transverse section, and a plurality of center transverse sections, said sections extending from side to side of the assembly and having stepped transverse abutting walls, said sections being joined together along said abutting walls to form a block, each section including a crankcase porticn and transversely spaced cylinder locating portions the axes of which coincide with the abutting walls of each section adjacent said locating portions, said crankcase portions being axially aligned longitudinally of the block assembly and said cylinder locating portions comprising curved, re-entrant, opensided, oppositely directed and correspondingly positioned recesses located in said abutting transverse walls and coacting to define circular openings located partly in each of said sections, the centers of curvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said openings having their axes substantially radial with respect to, and longitudinally spaced along, the longitudinal axes of the crankcase portions.

9. In a V-type cylinder block assembly, a plurality of transverse sections extending from side to side of the assembly and having transverse abutting walls, said sections being joined together along said abutting walls to form a block, each section including a crankcase portion and transversely spaced cylinder locating portions the axes of which are offset with respect to said abutting walls, said crankcase portions being axially aligned longitudinally of the block assembly, each of said crankcase portions also provided with an opening adapted to accommodate a cam shaft therein and a recess adapted to serve as an upper support for a crankshaft bearing, said cylinder locating portions comprising curved, re-entrant, open-sided, oppositely directed and correspondingly positioned recesses located in said abutting transverse walls and coacting to define circular openings located in each of said sections, the centers of curvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said openings having their axes substantially radial with respect to, and longitudinally spaced along, the longitudinal axis of the crankcase portions.

10. In a V-type cylinder block assembly, a plurality of transverse sections extending from side to side of the assembly and having stepped transverse abutting walls, said sections being joined together along such abutting walls to form a block, each section including a crankcase portion and transversely spaced cylinder locating portions the axes of which coincide with the abutting walls of each section adjacent said locating portions, said crankcase portions being axially aligned longitudinally of the block assembly, each of said crankcase portions also provided with an opening adapted to accommodate a cam shaft therein and a recess adapted to serve as an upper support for a crankshaft bearing, said cylinder locating portions comprising curved, re-entrant, open-sided, oppositely directed and correspondingly positioned recesses located in said stepped abutting transverse walls and coacting to define circular openings located partly in each of said sections, the centers of curvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said cylinder locating portions also having their axes substantially radial with respect to, and longitudinally spaced along, the longitudinal axis of the crankcase portions.

ll. In a V-type cylinder block assembly, a plurality of transversesections extending from side to side of the assembly and having transverse abutting walls, a plurality of cylinder liners, said sections being joined together along said abutting walls to form a block, each section including a crankcase portion and transversely spaced cylinder locating portions, said crankcase portions being axially aligned longitudinally of the block assembly, said cylinder locating portions comprising curved, re-entrant, open-sided, oppositely directed and correspondingly positioned recesses located in said abutting transverse walls and coacting to define circular openings partly in each of said sections, the centers of curvature of the recesses in each of said sections being spaced with respect to each other longitudinally of said block, said openings having their axes substantially radial with respect to, and longitudinally spaced along, the longitudinal axis of the crankcase portions, said cylinder liners being inserted in said openings and joined to adjacent sections of said assembly.

References Cited in the file of this patent UNITED STATES PATENTS 1,402,695 Wall Jan. 3, 1922 2,189,600 Daub Feb. 6, 1940 2,397,434 Ricart Mar. 26, 1946 2,426,877 Willgoos et al. Sept. 2, 1947 2,486,927 Chapman et a1 Nov. 1, 1949 2,491,630 Voorhies Dec. 20, 1949 FOREIGN PATENTS 259,313 Great Britain Oct. 11, 1926 

